EFFICIENT PRODUCTION writ large

23.01.2013

Robot-supported workpiece handling ensures up to 8000 hours of useful production time on CNC high-performance machining centers.

As a pioneer of medical technology for orthopaedics, Stryker has developed over more than 80 years to become a global group with its own development and production sites in the USA, Puerto Rico, Ireland, China, Germany, France and Switzerland. Consistently adapting to meet market requirements, each site has specific qualifications above and beyond the standard range. For example, the Swiss subsidiary Stryker Osteosynthesis in Selzach is specialized in development and production of implants, plates and external fixings, including associated instruments. Despite rather small series production, the technology is relatively highly automated.

365 DAYS X 18-24 HOURS = 3.5 M FINISHED PARTS PER ANNUM

"Of our 410 employees, around 60 are active in development, 80 in quality assurance and 200 in production," says Gerhard Hänggi, Director of Manufacturing at Stryker Osteosynthesis. Depending on what is on the order books, production staff, working in a variety of shift models operating 115 CNC production machines, produce up to 3.5 million finished parts per year, even despite small batch production of between 10 and 500 units. "However, the number of variants is especially high, with more than several thousand active parts. As a result, we have deployed an inter-disciplinary 'island production' system with equally high degrees of productivity and flexibility." The machine concept for 5-axis complete and simultaneous machining - with 3 axes in the tool and 2 axes in the workpiece - was very quickly convincing. Machining tests and the resulting high quality, reproducible precision machining were just what we needed a good five years ago to opt for the Hermle C 20 solution.

PRODUCTIVITY THANKS TO FLEXIBILITY AND AUTOMATION

When the company was ready to acquire additional CNC 5-axis machining centers with integrated highly automated part feeding, Hermle once again gave a convincing presentation of its full range of services. Currently, Stryker now has a C 20 U (with externally automated workpiece handling), a C 30 U (for production and prototype manufacturing) and two C 30 U with the RS 05 robot system for automated production. When combined with an NC-swivelling rotary table and the large working space (traverse paths X=650, Y=600 and Z=500 mm) and tool magazine and robotic automated workpiece handling, the C 30 U systems can be used anywhere. They also have a Renishaw touch probe and a tool breakage and measurement system from Blum. While previously it was necessary to use a separate machine for each individual process, today our machining centers with RS 05 can do all the tasks in one run", says Markus Lindt, summarizing the benefits

THIS IS WHAT TRUE PARTNERSHIP LOOKS LIKE

Stryker has ambitious aims in respect of improving the quantity and especially quality of its production. "Now we have found the right systems for our requirements," reports their Head of Implant Production. "Anyone who, like us, wants to produce 7000 and more hours per year needs consistent automation and as good as no downtime at all. With the technologies and services from Hermle, we're on the right track in all respects. And thanks to our experience with robots, we also found the change to robot-supported loading of the machining centers to be quite easy. The fact that Hermle also considered our specific handling and magazine requirements in the construction of the systems, and that the entire team demonstrated exemplary speed of response, has just confirmed to us again that we have chosen the right partner."